#include <stdio.h>
int main(int argc,char *argv[])
{
	if(argc<3)
	{
		printf("Usage:%s old_name new_name\n",argv[0]);
		return;
	}
	printf("%s => %s",argv[1],argv[2]);
	if(rename(argv[1],argv[2])<0)
		printf("[error!]\n");
	else
		printf("[OK!]\n");
	return 0;
}